Int 2C Fn 0029  P - Cloaking - Set Secondary Stack                         [m]

   AX = 0029h
   DX:EBX = new value for SS:ESP of ring 3 secondary stack

Return: CF clear
Desc:  inform RM386 of the ring 3 interrupt stack location

Note:  this function was first introduced with RM386 (RAM-MAN/386) v6.00